Related Experiment Video

Updated: May 25, 2026

Identification of Novel CK2 Kinase Substrates Using a Versatile Biochemical Approach
11:11

Identification of Novel CK2 Kinase Substrates Using a Versatile Biochemical Approach

Published on: February 21, 2019

Regulation of CK2 by phosphorylation and O-GlcNAcylation revealed by semisynthesis

Mary Katherine Tarrant1, Hee-Sool Rho, Zhi Xie

  • 1Department of Pharmacology and Molecular Sciences, The Johns Hopkins University School of Medicine, Baltimore, Maryland, USA.

Nature Chemical Biology
|January 24, 2012
PubMed

Insights

Casein kinase II (CK2) activity is regulated by post-translational modifications. O-linked glycosylation and phosphorylation of CK2α impact its stability and substrate selectivity, revealing novel regulatory mechanisms.

Area of Science:

  • Biochemistry
  • Molecular Biology
  • Cellular Signaling

Background:

  • Casein kinase II (CK2) is a serine-threonine kinase crucial for cell growth and proliferation.
  • The precise regulatory mechanisms governing CK2 function remain largely unelucidated.

Purpose of the Study:

  • To investigate the regulatory roles of O-linked β-N-acetyl-glucosamine (O-GlcNAc) glycosylation and phosphorylation on the CK2 catalytic subunit (CK2α).
  • To elucidate how these post-translational modifications affect CK2α stability, protein interactions, and substrate selectivity.

Main Methods:

  • Protein semisynthesis was employed to generate site-specifically modified CK2α.
  • Kinase assays were performed using human protein microarrays with modified CK2α, CK2β, and Pin1.

Main Results:

  • Phosphorylation of CK2α at Thr344 enhances stability by strengthening Pin1 interaction.
  • O-GlcNAc glycosylation at Ser347 antagonizes Thr344 phosphorylation and promotes proteasomal degradation.
  • Post-translational modifications of CK2α modulate its substrate selectivity.

Conclusions:

  • CK2α is subject to multi-level regulation through distinct post-translational modifications.
  • Glycosylation and phosphorylation act antagonistically to fine-tune CK2 activity and biological outputs.
  • This study provides insights into the regulation of a promiscuous protein kinase.

More Related Videos

Identification of Cyclin-dependent Kinase 1 Specific Phosphorylation Sites by an In Vitro Kinase Assay12:26

Identification of Cyclin-dependent Kinase 1 Specific Phosphorylation Sites by an In Vitro Kinase Assay

Published on: May 3, 2018

Identification of Kinase-substrate Pairs Using High Throughput Screening11:13

Identification of Kinase-substrate Pairs Using High Throughput Screening

Published on: August 29, 2015

Related Concept Videos

Phosphorylation01:02

Phosphorylation

The addition or removal of phosphate groups from proteins is the most common chemical modification that regulates cellular processes. These modifications can affect the structure, activity, stability, and localization of proteins within cells as well as their interactions with other proteins.
During phosphorylation, protein kinases transfer the terminal phosphate group of ATP to specific amino acid side chains of substrate proteins. Serine, threonine, and tyrosine are the most commonly...
Phosphorylation01:02

Phosphorylation

The addition or removal of phosphate groups from proteins is the most common chemical modification that regulates cellular processes. These modifications can affect the structure, activity, stability, and localization of proteins within cells as well as their interactions with other proteins.
During phosphorylation, protein kinases transfer the terminal phosphate group of ATP to specific amino acid side chains of substrate proteins. Serine, threonine, and tyrosine are the most commonly...
Covalently Linked Protein Regulators02:04

Covalently Linked Protein Regulators

Proteins can undergo many types of post-translational modifications, often in response to changes in their environment. These modifications play an important role in the function and stability of these proteins. Covalently linked molecules include functional groups, such as methyl, acetyl, and phosphate groups, and also small proteins, such as ubiquitin. There are around 200 different types of covalent regulators that have been identified.
These groups modify specific amino acids in a protein.
Protein Kinases and Phosphatases02:54

Protein Kinases and Phosphatases

Proteins undergo chemical modifications that trigger changes in the charge, structure, and conformation of the proteins. Phosphorylation, acetylation, glycosylation, nitrosylation, ubiquitination, lipidation, methylation, and proteolysis are various protein modifications that regulate protein activity. Such modifications are usually enzyme-driven.
Protein kinases
Many proteins in the cell are regulated by phosphorylation, the addition of a phosphate group. A family of enzymes called kinases...
Inhibition of Cdk Activity02:34

Inhibition of Cdk Activity

The orderly progression of the cell cycle depends on the activation of Cdk protein by binding to its cyclin partner. However, the cell cycle must be restricted when undergoing abnormal changes. Most cancers correlate to the deregulated cell cycle, and since Cdks are a central component of the cell cycle, Cdk inhibitors are extensively studied to develop anticancer agents. For instance, cyclin D associates with several Cdks, such as Cdk 4/6, to form an active complex. The cyclin D-Cdk4/6 complex...
Calmodulin-dependent Signaling01:16

Calmodulin-dependent Signaling

Calmodulin (CaM) is a calcium-binding protein in eukaryotes that controls various calcium-regulated cellular processes. It has four calcium-binding sites that bind calcium to form the calcium-calmodulin ( Ca2+-CaM) complex. GPCR stimulation increases the calcium levels in the cells that bind to CaM and induces a conformational change.
The Ca2+-CaM complex does not have enzymatic activity by itself. Instead, the complex binds downstream target proteins, including membrane proteins or enzymes,...